LLD doesn't support common-page-size=value keyword #31

tpimh · 2018-09-06T07:04:22Z

I just remove this option and it works fine without it.

diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index fa3f439..293fa4c 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -47,7 +47,7 @@ targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
 CPPFLAGS_vdso.lds += -P -C

 VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
-                       -z max-page-size=4096 -z common-page-size=4096
+                       -z max-page-size=4096

 $(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
        $(call if_changed,vdso)
@@ -92,7 +92,7 @@ CFLAGS_REMOVE_vvar.o = -pg

 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
-                          -z max-page-size=4096 -z common-page-size=4096
+                          -z max-page-size=4096

 # x32-rebranded versions
 vobjx32s-y := $(vobjs-y:.o=-x32.o)

nickdesaulniers · 2018-09-06T18:34:52Z

I'd be curious if this can be masked out with ld-option or is required. Will need to take a look at the documentation to see what it does.

nickdesaulniers · 2018-10-15T01:25:22Z

man 1 ld:

           common-page-size=value
               Set the page size most commonly used to value.  Memory image layout will be
               optimized to minimize memory pages if the system is using pages of this size.

nickdesaulniers · 2018-10-15T01:36:19Z

Looks like lld has some strange handling of unknown flags that prevents ldoption from detecting support correctly.

➜  linux git:(master) ✗ ld.lld -z common-page-size=4096 -v                         
LLD 8.0.0 (compatible with GNU linkers)
➜  linux git:(master) ✗ echo $?
0

➜  linux git:(master) ✗ ld.lld -adfasdf -v                
ld.lld: error: unknown argument: -adfasdf
LLD 8.0.0 (compatible with GNU linkers)
➜  linux git:(master) ✗ echo $?                           
1

➜  linux git:(master) ✗ ld.lld -z common-page-size=4096   
ld.lld: error: unknown -z value: common-page-size=4096
➜  linux git:(master) ✗ echo $?                        
1

So it seems that -v can mask invalid -z values, which is problematic for how the Linux kernel's KBUILD build system detects linker flag support.

Once that's fixed, we could do:

diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 141d415a8c80..4157e6fc7b15 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -47,7 +47,8 @@ targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
 CPPFLAGS_vdso.lds += -P -C
 
 VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
-			-z max-page-size=4096 -z common-page-size=4096
+			-z max-page-size=4096
+VDSO_LDFLAGS_vdso.lds += $(call ld-option, -z common-page-size=4096)
 
 $(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
 	$(call if_changed,vdso)
@@ -98,7 +99,8 @@ CFLAGS_REMOVE_vvar.o = -pg
 
 CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
 VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
-			   -z max-page-size=4096 -z common-page-size=4096
+			   -z max-page-size=4096
+VDSO_LDFLAGS_vdsox32.lds += $(call ld-option, -z common-page-size=4096)
 
 # x32-rebranded versions
 vobjx32s-y := $(vobjs-y:.o=-x32.o)

but it might be nice to add support for the flag outright.

nickdesaulniers · 2018-10-15T01:47:08Z

LLVM Bugs:

tpimh · 2018-10-15T06:05:41Z

I already reported the first one: Support common-page-size=value keyword. Sorry for not linking it here.

Increase kasan instrumented kernel stack size from 32k to 64k. Other architectures seems to get away with just doubling kernel stack size under kasan, but on s390 this appears to be not enough due to bigger frame size. The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting stack overflow is fs sync on xfs filesystem: #0 [9a0681e8] 704 bytes check_usage at 34b1fc #1 [9a0684a8] 432 bytes check_usage at 34c710 #2 [9a068658] 1048 bytes validate_chain at 35044a #3 [9a068a70] 312 bytes __lock_acquire at 3559fe #4 [9a068ba8] 440 bytes lock_acquire at 3576ee #5 [9a068d60] 104 bytes _raw_spin_lock at 21b44e0 #6 [9a068dc8] 1992 bytes enqueue_entity at 2dbf72 #7 [9a069590] 1496 bytes enqueue_task_fair at 2df5f0 #8 [9a069b68] 64 bytes ttwu_do_activate at 28f438 #9 [9a069ba8] 552 bytes try_to_wake_up at 298c4c #10 [9a069dd0] 168 bytes wake_up_worker at 23f97c #11 [9a069e78] 200 bytes insert_work at 23fc2e #12 [9a069f40] 648 bytes __queue_work at 2487c0 #13 [9a06a1c8] 200 bytes __queue_delayed_work at 24db28 #14 [9a06a290] 248 bytes mod_delayed_work_on at 24de84 #15 [9a06a388] 24 bytes kblockd_mod_delayed_work_on at 153e2a0 #16 [9a06a3a0] 288 bytes __blk_mq_delay_run_hw_queue at 158168c #17 [9a06a4c0] 192 bytes blk_mq_run_hw_queue at 1581a3c #18 [9a06a580] 184 bytes blk_mq_sched_insert_requests at 15a2192 #19 [9a06a638] 1024 bytes blk_mq_flush_plug_list at 1590f3a #20 [9a06aa38] 704 bytes blk_flush_plug_list at 1555028 #21 [9a06acf8] 320 bytes schedule at 219e476 #22 [9a06ae38] 760 bytes schedule_timeout at 21b0aac #23 [9a06b130] 408 bytes wait_for_common at 21a1706 #24 [9a06b2c8] 360 bytes xfs_buf_iowait at fa1540 #25 [9a06b430] 256 bytes __xfs_buf_submit at fadae6 #26 [9a06b530] 264 bytes xfs_buf_read_map at fae3f6 #27 [9a06b638] 656 bytes xfs_trans_read_buf_map at 10ac9a8 #28 [9a06b8c8] 304 bytes xfs_btree_kill_root at e72426 #29 [9a06b9f8] 288 bytes xfs_btree_lookup_get_block at e7bc5e #30 [9a06bb18] 624 bytes xfs_btree_lookup at e7e1a6 #31 [9a06bd88] 2664 bytes xfs_alloc_ag_vextent_near at dfa070 #32 [9a06c7f0] 144 bytes xfs_alloc_ag_vextent at dff3ca #33 [9a06c880] 1128 bytes xfs_alloc_vextent at e05fce #34 [9a06cce8] 584 bytes xfs_bmap_btalloc at e58342 #35 [9a06cf30] 1336 bytes xfs_bmapi_write at e618de #36 [9a06d468] 776 bytes xfs_iomap_write_allocate at ff678e #37 [9a06d770] 720 bytes xfs_map_blocks at f82af8 #38 [9a06da40] 928 bytes xfs_writepage_map at f83cd6 #39 [9a06dde0] 320 bytes xfs_do_writepage at f85872 #40 [9a06df20] 1320 bytes write_cache_pages at 73dfe8 #41 [9a06e448] 208 bytes xfs_vm_writepages at f7f892 #42 [9a06e518] 88 bytes do_writepages at 73fe6a #43 [9a06e570] 872 bytes __writeback_single_inode at a20cb6 #44 [9a06e8d8] 664 bytes writeback_sb_inodes at a23be2 #45 [9a06eb70] 296 bytes __writeback_inodes_wb at a242e0 #46 [9a06ec98] 928 bytes wb_writeback at a2500e #47 [9a06f038] 848 bytes wb_do_writeback at a260ae #48 [9a06f388] 536 bytes wb_workfn at a28228 #49 [9a06f5a0] 1088 bytes process_one_work at 24a234 #50 [9a06f9e0] 1120 bytes worker_thread at 24ba26 #51 [9a06fe40] 104 bytes kthread at 26545a #52 [9a06fea8] kernel_thread_starter at 21b6b62 To be able to increase the stack size to 64k reuse LLILL instruction in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE (65192) value as unsigned. Reported-by: Benjamin Block <bblock@linux.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

tpimh · 2018-11-27T15:22:56Z

This option is also used by the FreeBSD kernel.

nickdesaulniers · 2018-12-05T23:12:41Z

I've wrapped your patch above in the commit message:

    x86/vdso: drop implicit common-page-size linker flag
    
    These are implied by the target architecture and for x86_64 match the
    max-page-size. The default for non-NaCl x86_64 is 0x1000 (4096).

    In bfd the common page size is defined as 0x1000 (4096) for non-NaCl
    x86_64 targets:
    
    bfd/elf64-x86-64.c:
    4998:#define ELF_COMMONPAGESIZE             0x1000
    
    For gold, the common page size is defined as 0x1000 (4096) for non-NaCl
    x86_64 targets:
    
    gold/x86_64.cc:
    1413:  0x1000, // common_pagesize (overridable by -z common-page-size)
    1442:  0x1000, // common_pagesize (overridable by -z common-page-size)
    
    (ELF_COMMONPAGESIZE also defaults to ELF_MAXPAGESIZE when not set
    explicitly for a target architecture in bfd/elfxx-target.h, but that's
    not relevant for x86_64).
    
    Because it's implied by the target architecture, it's of questionable
    use to implement in LLD.  This patch resolves one of the issues towards
    using LLD to link an x86_64 kernel.

Doing some final internal testing and then hope to upstream soon/ASAP.

nickdesaulniers · 2018-12-05T23:15:49Z

@gwelymernans is also helping verify/test.

nickdesaulniers · 2018-12-06T19:14:34Z

https://lore.kernel.org/r/20181206191231.192355-1-ndesaulniers@google.com/

These are implied by the target architecture and for x86_64 match the max-page-size. The default for non-NaCl x86_64 is 0x1000 (4096). In bfd the common page size is defined as 0x1000 (4096) for non-NaCl x86_64 targets: bfd/elf64-x86-64.c: 4998:#define ELF_COMMONPAGESIZE 0x1000 For gold, the common page size is defined as 0x1000 (4096) for non-NaCl x86_64 targets: gold/x86_64.cc: 1413: 0x1000, // common_pagesize (overridable by -z common-page-size) 1442: 0x1000, // common_pagesize (overridable by -z common-page-size) (ELF_COMMONPAGESIZE also defaults to ELF_MAXPAGESIZE when not set explicitly for a target architecture in bfd/elfxx-target.h, but that's not relevant for x86_64). Because it's implied by the target architecture, it's of questionable use to implement in LLD. This patch resolves one of the issues towards using LLD to link an x86_64 kernel. Fixes commit 2aae950 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Link: https://bugs.llvm.org/show_bug.cgi?id=38774 Link: ClangBuiltLinux#31 Cc: Fangrui Song <maskray@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andi Kleen <andi@firstfloor.org> Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Bill Wendling <morbo@google.com> Suggested-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Rui Ueyama <ruiu@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

nickdesaulniers · 2018-12-07T18:54:07Z

accepted: https://git.kernel.org/tip/ac3e233d29f7f77f28243af0132057d378d3ea58

GNU linker's -z common-page-size's default value is based on the target architecture. arch/x86/entry/vdso/Makefile sets it to the architecture default, which is implicit and redundant. Drop it. Fixes: 2aae950 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Bill Wendling <morbo@google.com> Suggested-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Rui Ueyama <ruiu@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Fangrui Song <maskray@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20181206191231.192355-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=38774 Link: #31

nickdesaulniers · 2018-12-10T17:59:37Z

Fix landed in Linux 4.20-rc6

commit ac3e233 ("x86/vdso: Drop implicit common-page-size linker flag")

So this flag is still not supported in LLD, but it seems that this will be ok going forward; a break from binutils that makes sense IMO.

…ext bug With lockdep enabled, we will get following warning: ar9331_switch ethernet.1:10 lan0 (uninitialized): PHY [!ahb!ethernet@1a000000!mdio!switch@10:00] driver [Qualcomm Atheros AR9331 built-in PHY] (irq=13) BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 18, name: kworker/0:1 INFO: lockdep is turned off. irq event stamp: 602 hardirqs last enabled at (601): [<8073fde0>] _raw_spin_unlock_irq+0x3c/0x80 hardirqs last disabled at (602): [<8073a4f4>] __schedule+0x184/0x800 softirqs last enabled at (0): [<80080f60>] copy_process+0x578/0x14c8 softirqs last disabled at (0): [<00000000>] 0x0 CPU: 0 PID: 18 Comm: kworker/0:1 Not tainted 5.10.0-rc3-ar9331-00734-g7d644991df0c #31 Workqueue: events deferred_probe_work_func Stack : 80980000 80980000 8089ef70 80890000 804b5414 80980000 00000002 80b53728 00000000 800d1268 804b5414 ffffffde 00000017 800afe08 81943860 0f5bfc32 00000000 00000000 8089ef70 819436c0 ffffffea 00000000 00000000 00000000 8194390c 808e353c 0000000f 66657272 80980000 00000000 00000000 80890000 804b5414 80980000 00000002 80b53728 00000000 00000000 00000000 80d40000 ... Call Trace: [<80069ce0>] show_stack+0x9c/0x140 [<800afe08>] ___might_sleep+0x220/0x244 [<8073bfb0>] __mutex_lock+0x70/0x374 [<8073c2e0>] mutex_lock_nested+0x2c/0x38 [<804b5414>] regmap_update_bits_base+0x38/0x8c [<804ee584>] regmap_update_bits+0x1c/0x28 [<804ee714>] ar9331_sw_unmask_irq+0x34/0x60 [<800d91f0>] unmask_irq+0x48/0x70 [<800d93d4>] irq_startup+0x114/0x11c [<800d65b4>] __setup_irq+0x4f4/0x6d0 [<800d68a0>] request_threaded_irq+0x110/0x190 [<804e3ef0>] phy_request_interrupt+0x4c/0xe4 [<804df508>] phylink_bringup_phy+0x2c0/0x37c [<804df7bc>] phylink_of_phy_connect+0x118/0x130 [<806c1a64>] dsa_slave_create+0x3d0/0x578 [<806bc4ec>] dsa_register_switch+0x934/0xa20 [<804eef98>] ar9331_sw_probe+0x34c/0x364 [<804eb48c>] mdio_probe+0x44/0x70 [<8049e3b4>] really_probe+0x30c/0x4f4 [<8049ea10>] driver_probe_device+0x264/0x26c [<8049bc10>] bus_for_each_drv+0xb4/0xd8 [<8049e684>] __device_attach+0xe8/0x18c [<8049ce58>] bus_probe_device+0x48/0xc4 [<8049db70>] deferred_probe_work_func+0xdc/0xf8 [<8009ff64>] process_one_work+0x2e4/0x4a0 [<800a0770>] worker_thread+0x2a8/0x354 [<800a774c>] kthread+0x16c/0x174 [<8006306c>] ret_from_kernel_thread+0x14/0x1c ar9331_switch ethernet.1:10 lan1 (uninitialized): PHY [!ahb!ethernet@1a000000!mdio!switch@10:02] driver [Qualcomm Atheros AR9331 built-in PHY] (irq=13) DSA: tree 0 setup To fix it, it is better to move access to MDIO register to the .irq_bus_sync_unlock call back. Fixes: ec6698c ("net: dsa: add support for Atheros AR9331 built-in switch") Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Link: https://lore.kernel.org/r/20201211110317.17061-1-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>

commit ac3e233d29f7f77f28243af0132057d378d3ea58 upstream. GNU linker's -z common-page-size's default value is based on the target architecture. arch/x86/entry/vdso/Makefile sets it to the architecture default, which is implicit and redundant. Drop it. Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Bill Wendling <morbo@google.com> Suggested-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Rui Ueyama <ruiu@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Fangrui Song <maskray@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20181206191231.192355-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=38774 Link: ClangBuiltLinux/linux#31 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

GNU linker's -z common-page-size's default value is based on the target architecture. arch/x86/entry/vdso/Makefile sets it to the architecture default, which is implicit and redundant. Drop it. Fixes: 2aae950 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Bill Wendling <morbo@google.com> Suggested-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Rui Ueyama <ruiu@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Fangrui Song <maskray@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20181206191231.192355-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=38774 Link: ClangBuiltLinux/linux#31 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

commit ac3e233d29f7f77f28243af0132057d378d3ea58 upstream. GNU linker's -z common-page-size's default value is based on the target architecture. arch/x86/entry/vdso/Makefile sets it to the architecture default, which is implicit and redundant. Drop it. Fixes: 2aae950 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Bill Wendling <morbo@google.com> Suggested-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Rui Ueyama <ruiu@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Fangrui Song <maskray@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20181206191231.192355-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=38774 Link: ClangBuiltLinux/linux#31 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

commit ac3e233d29f7f77f28243af0132057d378d3ea58 upstream. GNU linker's -z common-page-size's default value is based on the target architecture. arch/x86/entry/vdso/Makefile sets it to the architecture default, which is implicit and redundant. Drop it. Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Bill Wendling <morbo@google.com> Suggested-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Rui Ueyama <ruiu@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Fangrui Song <maskray@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20181206191231.192355-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=38774 Link: ClangBuiltLinux/linux#31 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>

These are implied by the target architecture and for x86_64 match the max-page-size. The default for non-NaCl x86_64 is 0x1000 (4096). In bfd the common page size is defined as 0x1000 (4096) for non-NaCl x86_64 targets: bfd/elf64-x86-64.c: 4998:#define ELF_COMMONPAGESIZE 0x1000 For gold, the common page size is defined as 0x1000 (4096) for non-NaCl x86_64 targets: gold/x86_64.cc: 1413: 0x1000, // common_pagesize (overridable by -z common-page-size) 1442: 0x1000, // common_pagesize (overridable by -z common-page-size) (ELF_COMMONPAGESIZE also defaults to ELF_MAXPAGESIZE when not set explicitly for a target architecture in bfd/elfxx-target.h, but that's not relevant for x86_64). Because it's implied by the target architecture, it's of questionable use to implement in LLD. This patch resolves one of the issues towards using LLD to link an x86_64 kernel. Fixes commit 2aae950 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu") Change-Id: If8c517223f705dc5d2dac43ebeb1fac1c6a9d484 Link: https://bugs.llvm.org/show_bug.cgi?id=38774 Link: ClangBuiltLinux/linux#31 Cc: Fangrui Song <maskray@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andi Kleen <andi@firstfloor.org> Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Bill Wendling <morbo@google.com> Suggested-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Rui Ueyama <ruiu@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Adam W. Willis <return.of.octobot@gmail.com> Signed-off-by: mcdachpappe <noreference@web.de>